src/FDM/JSBSim/FGAircraft.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGAircraft.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 12/12/98
   6  Purpose:      Encapsulates an aircraft
   7  Called by:    FGFDMExec
   8
   9  ------------- Copyright (C) 1999  Jon S. Berndt (jsb@hal-pc.org) -------------
  10
  11  This program is free software; you can redistribute it and/or modify it under
  12  the terms of the GNU General Public License as published by the Free Software
  13  Foundation; either version 2 of the License, or (at your option) any later
  14  version.
  15
  16  This program is distributed in the hope that it will be useful, but WITHOUT
  17  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  18  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  19  details.
  20
  21  You should have received a copy of the GNU General Public License along with
  22  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  23  Place - Suite 330, Boston, MA  02111-1307, USA.
  24
  25  Further information about the GNU General Public License can also be found on
  26  the world wide web at http://www.gnu.org.
  27
  28 FUNCTIONAL DESCRIPTION
  29 --------------------------------------------------------------------------------
  30 Models the aircraft reactions and forces. This class is instantiated by the
  31 FGFDMExec class and scheduled as an FDM entry.
  32
  33 HISTORY
  34 --------------------------------------------------------------------------------
  35 12/12/98   JSB   Created
  36 04/03/99   JSB   Changed Aero() method to correct body axis force calculation
  37                  from wind vector. Fix provided by Tony Peden.
  38 05/03/99   JSB   Changed (for the better?) the way configurations are read in.
  39 9/17/99     TP   Combined force and moment functions. Added aero reference
  40                  point to config file. Added calculations for moments due to
  41                  difference in cg and aero reference point
  42
  43 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  44 COMMENTS, REFERENCES,  and NOTES
  45 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  46
  47 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  48 INCLUDES
  49 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  50
  51 #include <sys/stat.h>
  52 #include <sys/types.h>
  53
  54 #ifdef FGFS
  55 #  ifndef __BORLANDC__
  56 #    include <simgear/compiler.h>
  57 #  endif
  58 #  ifdef SG_HAVE_STD_INCLUDES
  59 #    include <cmath>
  60 #  else
  61 #    include <math.h>
  62 #  endif
  63 #else
  64 #  if defined (sgi) && !defined(__GNUC__)
  65 #    include <math.h>
  66 #  else
  67 #    include <cmath>
  68 #  endif
  69 #endif
  70
  71 #include "FGAircraft.h"
  72 #include "FGMassBalance.h"
  73 #include "FGInertial.h"
  74 #include "FGGroundReactions.h"
  75 #include "FGAerodynamics.h"
  76 #include "FGTranslation.h"
  77 #include "FGRotation.h"
  78 #include "FGAtmosphere.h"
  79 #include "FGState.h"
  80 #include "FGFDMExec.h"
  81 #include "FGFCS.h"
  82 #include "FGPosition.h"
  83 #include "FGAuxiliary.h"
  84 #include "FGOutput.h"
  85 #include "FGPropertyManager.h"
  86
  87 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  88 DEFINITIONS
  89 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  90
  91 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  92 GLOBAL DATA
  93 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  94
  95 static const char *IdSrc = "$Id$";
  96 static const char *IdHdr = ID_AIRCRAFT;
  97
  98 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  99 CLASS IMPLEMENTATION
 100 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 101
 102 FGAircraft::FGAircraft(FGFDMExec* fdmex) : FGModel(fdmex)
 103 {
 104   Name = "FGAircraft";
 105   WingIncidence   = 0.0;
 106   impending_stall = stall_hyst = 0.0;
 107   alphaclmin = alphaclmax = 0.0;
 108   alphahystmin = alphahystmax = 0.0;
 109   HTailArea = VTailArea = 0.0;
 110   HTailArm  = VTailArm  = 0.0;
 111   lbarh = lbarv = 0.0;
 112   vbarh = vbarv = 0.0;
 113   bi2vel = ci2vel = 0.0;
 114   alphaw = 0.0;
 115
 116   bind();
 117
 118   Debug(0);
 119 }
 120
 121 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 122
 123 FGAircraft::~FGAircraft()
 124 {
 125   unbind();
 126   Debug(1);
 127 }
 128
 129 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 130
 131 bool FGAircraft::Run(void)
 132 {
 133   double twovel;
 134   double alpha;
 135
 136   if (!FGModel::Run()) {                 // if false then execute this Run()
 137     vForces.InitMatrix();
 138     vForces += Aerodynamics->GetForces();
 139     vForces += Inertial->GetForces();
 140     vForces += Propulsion->GetForces();
 141     vForces += GroundReactions->GetForces();
 142
 143     vMoments.InitMatrix();
 144     vMoments += Aerodynamics->GetMoments();
 145     vMoments += Propulsion->GetMoments();
 146     vMoments += GroundReactions->GetMoments();
 147
 148     vBodyAccel = vForces/MassBalance->GetMass();
 149
 150     vNcg = vBodyAccel/Inertial->gravity();
 151
 152     vNwcg = State->GetTb2s() * vNcg;
 153     vNwcg(3) = -1*vNwcg(3) + 1;
 154
 155     twovel = 2*Translation->GetVt();
 156     if (twovel > 0) {
 157       bi2vel = WingSpan / twovel;
 158       ci2vel = cbar / twovel;
 159     }
 160
 161     alphaw = Translation->Getalpha() + WingIncidence;
 162
 163     alpha=Translation->Getalpha();
 164
 165     if (alphaclmax != 0) {
 166       if (alpha > 0.85*alphaclmax) {
 167         impending_stall = 10*(alpha/alphaclmax - 0.85);
 168       } else {
 169         impending_stall = 0;
 170       }
 171
 172     }
 173     if(alphahystmax != 0.0 && alphahystmin != 0.0) {
 174           if( alpha > alphahystmax ) {
 175             stall_hyst = 1;
 176           } else if(alpha < alphahystmin) {
 177             stall_hyst = 0;
 178           }
 179     }
 180
 181
 182
 183     return false;
 184   } else {                               // skip Run() execution this time
 185     return true;
 186   }
 187 }
 188
 189 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 190
 191 float FGAircraft::GetNlf(void)
 192 {
 193   return -1*Aerodynamics->GetvFs(3)/MassBalance->GetWeight();
 194 }
 195
 196 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 197
 198 bool FGAircraft::Load(FGConfigFile* AC_cfg)
 199 {
 200   string token = "";
 201   string parameter;
 202   double EW, bixx, biyy, bizz, bixy, bixz;
 203   double pmWt, pmX, pmY, pmZ;
 204   FGColumnVector3 vbaseXYZcg;
 205
 206   AC_cfg->GetNextConfigLine();
 207
 208   while ((token = AC_cfg->GetValue()) != string("/METRICS")) {
 209     *AC_cfg >> parameter;
 210     if (parameter == "AC_WINGAREA") {
 211       *AC_cfg >> WingArea;
 212       if (debug_lvl > 0) cout << "    WingArea: " << WingArea  << endl;
 213     } else if (parameter == "AC_WINGSPAN") {
 214       *AC_cfg >> WingSpan;
 215       if (debug_lvl > 0) cout << "    WingSpan: " << WingSpan  << endl;
 216     } else if (parameter == "AC_WINGINCIDENCE") {
 217       *AC_cfg >> WingIncidence;
 218       if (debug_lvl > 0) cout << "    Chord: " << cbar << endl;
 219     } else if (parameter == "AC_CHORD") {
 220       *AC_cfg >> cbar;
 221       if (debug_lvl > 0) cout << "    Chord: " << cbar << endl;
 222     } else if (parameter == "AC_HTAILAREA") {
 223       *AC_cfg >> HTailArea;
 224       if (debug_lvl > 0) cout << "    H. Tail Area: " << HTailArea << endl;
 225     } else if (parameter == "AC_HTAILARM") {
 226       *AC_cfg >> HTailArm;
 227       if (debug_lvl > 0) cout << "    H. Tail Arm: " << HTailArm << endl;
 228     } else if (parameter == "AC_VTAILAREA") {
 229       *AC_cfg >> VTailArea;
 230       if (debug_lvl > 0) cout << "    V. Tail Area: " << VTailArea << endl;
 231     } else if (parameter == "AC_VTAILARM") {
 232       *AC_cfg >> VTailArm;
 233       if (debug_lvl > 0) cout << "    V. Tail Arm: " << VTailArm << endl;
 234     } else if (parameter == "AC_IXX") {
 235       *AC_cfg >> bixx;
 236       if (debug_lvl > 0) cout << "    baseIxx: " << bixx << endl;
 237       MassBalance->SetBaseIxx(bixx);
 238     } else if (parameter == "AC_IYY") {
 239       *AC_cfg >> biyy;
 240       if (debug_lvl > 0) cout << "    baseIyy: " << biyy << endl;
 241       MassBalance->SetBaseIyy(biyy);
 242     } else if (parameter == "AC_IZZ") {
 243       *AC_cfg >> bizz;
 244       if (debug_lvl > 0) cout << "    baseIzz: " << bizz << endl;
 245       MassBalance->SetBaseIzz(bizz);
 246     } else if (parameter == "AC_IXY") {
 247       *AC_cfg >> bixy;
 248       if (debug_lvl > 0) cout << "    baseIxy: " << bixy  << endl;
 249       MassBalance->SetBaseIxy(bixy);
 250     } else if (parameter == "AC_IXZ") {
 251       *AC_cfg >> bixz;
 252       if (debug_lvl > 0) cout << "    baseIxz: " << bixz  << endl;
 253       MassBalance->SetBaseIxz(bixz);
 254     } else if (parameter == "AC_EMPTYWT") {
 255       *AC_cfg >> EW;
 256       MassBalance->SetEmptyWeight(EW);
 257       if (debug_lvl > 0) cout << "    EmptyWeight: " << EW  << endl;
 258     } else if (parameter == "AC_CGLOC") {
 259       *AC_cfg >> vbaseXYZcg(eX) >> vbaseXYZcg(eY) >> vbaseXYZcg(eZ);
 260       MassBalance->SetBaseCG(vbaseXYZcg);
 261       if (debug_lvl > 0) cout << "    CG (x, y, z): " << vbaseXYZcg << endl;
 262     } else if (parameter == "AC_EYEPTLOC") {
 263       *AC_cfg >> vXYZep(eX) >> vXYZep(eY) >> vXYZep(eZ);
 264       if (debug_lvl > 0) cout << "    Eyepoint (x, y, z): " << vXYZep << endl;
 265     } else if (parameter == "AC_AERORP") {
 266       *AC_cfg >> vXYZrp(eX) >> vXYZrp(eY) >> vXYZrp(eZ);
 267       if (debug_lvl > 0) cout << "    Ref Pt (x, y, z): " << vXYZrp << endl;
 268     } else if (parameter == "AC_ALPHALIMITS") {
 269       *AC_cfg >> alphaclmin >> alphaclmax;
 270       if (debug_lvl > 0) cout << "    Maximum Alpha: " << alphaclmax
 271              << "    Minimum Alpha: " << alphaclmin
 272              << endl;
 273     } else if (parameter == "AC_HYSTLIMITS") {
 274       *AC_cfg >> alphahystmin >> alphahystmax;
 275       if (debug_lvl > 0) cout << "    Hysteresis Start: " << alphahystmax
 276              << "    Hysteresis End: " << alphahystmin
 277              << endl;
 278     } else if (parameter == "AC_POINTMASS") {
 279       *AC_cfg >> pmWt >> pmX >> pmY >> pmZ;
 280       MassBalance->AddPointMass(pmWt, pmX, pmY, pmZ);
 281       if (debug_lvl > 0) cout << "    Point Mass Object: " << pmWt << " lbs. at "
 282                          << "X, Y, Z (in.): " << pmX << "  " << pmY << "  " << pmZ
 283                          << endl;
 284     }
 285   }
 286
 287   // calculate some derived parameters
 288   if (cbar != 0.0) {
 289     lbarh = HTailArm/cbar;
 290     lbarv = VTailArm/cbar;
 291     if (WingArea != 0.0) {
 292       vbarh = HTailArm*HTailArea / (cbar*WingArea);
 293       vbarv = VTailArm*VTailArea / (cbar*WingArea);
 294     }
 295   }
 296   return true;
 297 }
 298
 299 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 300
 301 void FGAircraft::bind(void)
 302 {
 303   typedef double (FGAircraft::*PMF)(int) const;
 304   PropertyManager->Tie("metrics/Sw-sqft", this,
 305                        &FGAircraft::GetWingArea);
 306   PropertyManager->Tie("metrics/bw-ft", this,
 307                        &FGAircraft::GetWingSpan);
 308   PropertyManager->Tie("metrics/cbarw-ft", this,
 309                        &FGAircraft::Getcbar);
 310   PropertyManager->Tie("metrics/iw-deg", this,
 311                        &FGAircraft::GetWingIncidence);
 312   PropertyManager->Tie("metrics/Sh-sqft", this,
 313                        &FGAircraft::GetHTailArea);
 314   PropertyManager->Tie("metrics/lh-ft", this,
 315                        &FGAircraft::GetHTailArm);
 316   PropertyManager->Tie("metrics/Sv-sqft", this,
 317                        &FGAircraft::GetVTailArea);
 318   PropertyManager->Tie("metrics/lv-ft", this,
 319                        &FGAircraft::GetVTailArm);
 320   PropertyManager->Tie("metrics/lh-norm", this,
 321                        &FGAircraft::Getlbarh);
 322   PropertyManager->Tie("metrics/lv-norm", this,
 323                        &FGAircraft::Getlbarv);
 324   PropertyManager->Tie("metrics/vbarh-norm", this,
 325                        &FGAircraft::Getvbarh);
 326   PropertyManager->Tie("metrics/vbarv-norm", this,
 327                        &FGAircraft::Getvbarv);
 328   PropertyManager->Tie("moments/l-total-lbsft", this,1,
 329                        (PMF)&FGAircraft::GetMoments);
 330   PropertyManager->Tie("moments/m-total-lbsft", this,2,
 331                        (PMF)&FGAircraft::GetMoments);
 332   PropertyManager->Tie("moments/n-total-lbsft", this,3,
 333                        (PMF)&FGAircraft::GetMoments);
 334   PropertyManager->Tie("forces/fbx-total-lbs", this,1,
 335                        (PMF)&FGAircraft::GetForces);
 336   PropertyManager->Tie("forces/fby-total-lbs", this,2,
 337                        (PMF)&FGAircraft::GetForces);
 338   PropertyManager->Tie("forces/fbz-total-lbs", this,3,
 339                        (PMF)&FGAircraft::GetForces);
 340   PropertyManager->Tie("metrics/aero-rp-x-ft", this,1,
 341                        (PMF)&FGAircraft::GetXYZrp);
 342   PropertyManager->Tie("metrics/aero-rp-y-ft", this,2,
 343                        (PMF)&FGAircraft::GetXYZrp);
 344   PropertyManager->Tie("metrics/aero-rp-z-ft", this,3,
 345                        (PMF)&FGAircraft::GetXYZrp);
 346   PropertyManager->Tie("metrics/eyepoint-x-ft", this,1,
 347                        (PMF)&FGAircraft::GetXYZep);
 348   PropertyManager->Tie("metrics/eyepoint-y-ft", this,2,
 349                        (PMF)&FGAircraft::GetXYZep);
 350   PropertyManager->Tie("metrics/eyepoint-z-ft", this,3,
 351                        (PMF)&FGAircraft::GetXYZep);
 352   PropertyManager->Tie("metrics/alpha-max-deg", this,
 353                        &FGAircraft::GetAlphaCLMax,
 354                        &FGAircraft::SetAlphaCLMax,
 355                        true);
 356   PropertyManager->Tie("metrics/alpha-min-deg", this,
 357                        &FGAircraft::GetAlphaCLMin,
 358                        &FGAircraft::SetAlphaCLMin,
 359                        true);
 360   PropertyManager->Tie("aero/bi2vel", this,
 361                        &FGAircraft::GetBI2Vel);
 362   PropertyManager->Tie("aero/ci2vel", this,
 363                        &FGAircraft::GetCI2Vel);
 364   PropertyManager->Tie("aero/alpha-wing-rad", this,
 365                        &FGAircraft::GetAlphaW);
 366   PropertyManager->Tie("systems/stall-warn-norm", this,
 367                         &FGAircraft::GetStallWarn);
 368   PropertyManager->Tie("aero/stall-hyst-norm", this,
 369                         &FGAircraft::GetHysteresisParm);
 370
 371 }
 372
 373 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 374
 375 void FGAircraft::unbind(void)
 376 {
 377   PropertyManager->Untie("metrics/Sw-sqft");
 378   PropertyManager->Untie("metrics/bw-ft");
 379   PropertyManager->Untie("metrics/cbarw-ft");
 380   PropertyManager->Untie("metrics/iw-deg");
 381   PropertyManager->Untie("metrics/Sh-sqft");
 382   PropertyManager->Untie("metrics/lh-ft");
 383   PropertyManager->Untie("metrics/Sv-sqft");
 384   PropertyManager->Untie("metrics/lv-ft");
 385   PropertyManager->Untie("metrics/lh-norm");
 386   PropertyManager->Untie("metrics/lv-norm");
 387   PropertyManager->Untie("metrics/vbarh-norm");
 388   PropertyManager->Untie("metrics/vbarv-norm");
 389   PropertyManager->Untie("moments/l-total-lbsft");
 390   PropertyManager->Untie("moments/m-total-lbsft");
 391   PropertyManager->Untie("moments/n-total-lbsft");
 392   PropertyManager->Untie("forces/fbx-total-lbs");
 393   PropertyManager->Untie("forces/fby-total-lbs");
 394   PropertyManager->Untie("forces/fbz-total-lbs");
 395   PropertyManager->Untie("metrics/aero-rp-x-ft");
 396   PropertyManager->Untie("metrics/aero-rp-y-ft");
 397   PropertyManager->Untie("metrics/aero-rp-z-ft");
 398   PropertyManager->Untie("metrics/eyepoint-x-ft");
 399   PropertyManager->Untie("metrics/eyepoint-y-ft");
 400   PropertyManager->Untie("metrics/eyepoint-z-ft");
 401   PropertyManager->Untie("metrics/alpha-max-deg");
 402   PropertyManager->Untie("metrics/alpha-min-deg");
 403   PropertyManager->Untie("aero/bi2vel");
 404   PropertyManager->Untie("aero/ci2vel");
 405   PropertyManager->Untie("aero/alpha-wing-rad");
 406   PropertyManager->Untie("systems/stall-warn-norm");
 407 }
 408
 409 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 410 //    The bitmasked value choices are as follows:
 411 //    unset: In this case (the default) JSBSim would only print
 412 //       out the normally expected messages, essentially echoing
 413 //       the config files as they are read. If the environment
 414 //       variable is not set, debug_lvl is set to 1 internally
 415 //    0: This requests JSBSim not to output any messages
 416 //       whatsoever.
 417 //    1: This value explicity requests the normal JSBSim
 418 //       startup messages
 419 //    2: This value asks for a message to be printed out when
 420 //       a class is instantiated
 421 //    4: When this value is set, a message is displayed when a
 422 //       FGModel object executes its Run() method
 423 //    8: When this value is set, various runtime state variables
 424 //       are printed out periodically
 425 //    16: When set various parameters are sanity checked and
 426 //       a message is printed out when they go out of bounds
 427
 428 void FGAircraft::Debug(int from)
 429 {
 430   if (debug_lvl <= 0) return;
 431
 432   if (debug_lvl & 1) { // Standard console startup message output
 433     if (from == 0) { // Constructor
 434     }
 435   }
 436   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 437     if (from == 0) cout << "Instantiated: FGAircraft" << endl;
 438     if (from == 1) cout << "Destroyed:    FGAircraft" << endl;
 439   }
 440   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 441   }
 442   if (debug_lvl & 8 ) { // Runtime state variables
 443   }
 444   if (debug_lvl & 16) { // Sanity checking
 445   }
 446   if (debug_lvl & 64) {
 447     if (from == 0) { // Constructor
 448       cout << IdSrc << endl;
 449       cout << IdHdr << endl;
 450     }
 451   }
 452 }
 453